The present invention relates to telephone answering and recording devices having the capability of playing back to a telephone caller a pre-recorded message and then recording any message from the caller.
In many of the conventional recording and answering devices, an endless loop of recording tape is used for pre-recording the broadcast message to be played to the caller. This is usually referred to as the broadcast tape. A second tape system, ordinarily having a reel-to-reel magnetic tape, is employed to record the messages from the callers.
The use of the endless tape for the playing of the pre-recorded message eliminates the need to periodically repeat the desired message along the entire length of the tape as well as the need for timing and switching systems for synchronizing the playing of the pre-recorded message and the recording the incoming message so they don't over lap one another. An example of an earlier one tape reel to reel system is U.S. Pat. No. 2,783,303.
In the conventional telephone answering devices, the endless recording tape has been known to include a strip of metallic foil of other means for switching the telephone answering device from one mode of operation to another, such as from the play-back to the record mode, as the endless tape completes a full revolution of 360.degree.. Various types of switching means associated with an endless belt are disclosed in U.S. Pat. No. 3,458,667.
Recording devices have also used an endless recording tape having one 180.degree. twist in the tape to increase the effective recording length of the endless tape. In particular, the device disclosed in the Patent to Burquez employes such an endless recording tape having a switching means, such as an off-centered hole in the tape or a strip of metallic foil on one side of the tape for switching receiving heads associated with each half-width of the twisted endless tape. This permits sequentially recording data on each half of the entire length of the endless belt, thereby increasing the effective length of the tape by a factor of two. The switching means on the twisted endless tape serves to alternately switch the receiving heads on each complete cycle of the endless recording tape.
Most of the previous telephone answering devices also employed some method for advising the caller that the telephone answering device was leaving the play back mode and was about to be switched into the record mode for recording the incoming message. In the standard telephone answering device this means consists of the use of a high frequency "beep," ordinarily obtained by feeding the output of an amplifier into the input, saturating the amplifier and resulting in a high frequency oscillatory signal.
One of the major goals in the designing of the telephone answering device has been the utilization of a system which is both efficient and at the same time as inexpensive as possible. Since there are essentially two complete systems in a telephone answering device the expense in manufacturing such telephone answering devices has resulted in a relatively high sales price for the product. Only by the use of multiple functions for many of the components and the capability of using inexpensive, yet reliable, components can the ultimate price of the telephone answering device be lowered so as to make the purchase price within the range available to the average consumer.
Also, in addition to being inexpensive and reliable, a certain minimal degree of quality must be achieved. A high noise level, normally the result of inexpensive components and simple mechanisms, will ordinarily be found unacceptable to a consumer of a product such as a telephone answering device.
Recording tape has two sides, one side being "rough." The rough side of a recording tape is that side of the tape which has been coated, ordinarily with a magnetic oxide, for recording. The non-coated side of the tape is smoother than the coated side.
In the present invention, the noise level normally produced when the rough side of the recording tape of the endless belt is drawn past a record-erase head of a tape recording system is minimized. This is achieved by the use of the endless belt in which there is one twist of 180 degrees, popularly known as the Mobius loop, so that while the tape recorder is in the recording mode, the endless loops has been inverted so that only the smooth surface of the endless belt is in contact with the record-erase head of the pre-recorded message record and play back systems.
It is therefore an object of the present invention to provide a telephone answering device which is less expensive than the previously available telephone answering devices.
An additional object of this invention is to provide a telephone answering device which is less expensive than the previously available telephone answering devices.
An additional object of this invention is to provide a device which utilizes, for the main part, commercially available recording instruments thus, reducing the extent of the manufacturing process and the resultant expense.
Another object is to provide a switching system which is reliable and is capable of using inexpensive switches.
A further object of the invention is to provide a telephone answering device which is simple to operate, reliable, and also has a high quality of sound reproduction.